code: def test_add_remark():
      """Test adding a REMARK entry."""
      # Add remark
      code = 3
      remark1 = "THIS IS A HIGHLY IMPORTANT FREE-TEXT REMARK WHICH IS EXACTLY 80 CHARACTERS LONG."
      remark2 = ""
      remark3 = "THIS IS A NEXT MULTI-LINE INDENTED REMARK\n FOLLOWING THE BLANK REMARK."
      ppdb = PandasPdb()
      ppdb.read_pdb(TESTDATA_FILENAME)
      n_atoms = len(ppdb.df["ATOM"])
      ppdb.add_remark(code, remark1)
      ppdb.add_remark(code, remark2)
      ppdb.add_remark(code, remark3, 5)
      ppdb.to_pdb(path=OUTFILE)
  
      # Test modified file contains remarks
      with open(OUTFILE, "r") as f:
          f1 = f.read()
      expected_substr = (
          "REMARK   3  OTHER REFINEMENT REMARKS: HYDROGENS HAVE BEEN ADDED IN THE RIDING   \n"
          "REMARK   3  POSITIONS                                                           \n"
          "REMARK   3 THIS IS A HIGHLY IMPORTANT FREE-TEXT REMARK WHICH IS EXACTLY 80      \n"
          "REMARK   3 CHARACTERS LONG.                                                     \n"
          "REMARK   3                                                                      \n"
          "REMARK   3      THIS IS A NEXT MULTI-LINE INDENTED REMARK                       \n"
          "REMARK   3      FOLLOWING THE BLANK REMARK.                                     \n"
          "REMARK   4                                                                      \n"
      )
      assert expected_substr in f1
  
      # Test number of atoms remained the same
      ppdb = PandasPdb()
      ppdb.read_pdb(OUTFILE)
      os.remove(OUTFILE)
      assert len(ppdb.df["ATOM"]) == n_atoms
  
file_path: biopandas/biopandas/pdb/tests/test_write_pdb.py
imports: from biopandas.pdb import PandasPdb
  import warnings
  import pandas
  import os
label_desc: Use image node_id 5 for calling a global function with example usage: test_add_remark() without return types